1. Field of the Invention
The present invention relates to network repeaters, more specifically to units incorporating two or more IEEE 802.3 compliant repeaters each operating at different data rates. The principle of monitoring link integrity and adjusting operating speed to minimize error rate may also be applied to other networking equipment, including (but not limited to): Bridges, Routers, Network interfaces and switches.
2. Background Art
Network repeaters are typically used to connect between network nodes, for example network stations serving as data terminal equipment (DTE) on different network media. Repeaters provide the advantage of extending the physical distance between network nodes by receiving a data packet from one network medium, reconditioning the physical signal, and outputting the data packet to a second network medium. The repeater may also forward carrier sense and collision signals, effectively extending the collision domain of one medium onto the second medium.
Repeaters interconnecting network nodes on different network media have conventionally been configured to connect only networks operating at the same transmission rate. One problem encountered in higher-speed networks, for example 100 Mb/s IEEE 802.3 networks, is the identification of a link, between the network repeater and a remote network node on one of the network repeater ports, having a poor level of integrity. In particular, there is a need to discover links between a repeater port and a network node that are not performing up to specifications, for example due to a poor cable connection or condition, a faulty network interface device at the remote node, etc.
One proposal for handling link failure is by using network management capabilities, for example, a remote management function (i.e., network manager) configured for monitoring and controlling operations of the repeater and the network nodes. For example, a remote management technique may use a management protocol to transmit management information between the repeater and the network manager. However, such an arrangement necessarily relies on a management function, and hence is inapplicable in unmanaged network. Moreover, the monitoring of links by a centralized network manager requires that each unit to be managed incorporate a function to handle the management protocol (an agent) increasing the complexity and processing requirements of the managed unit, e.g. a repeater.